1. Field of the Invention
The present invention relates to a capacitor.
2. Description of the Background Art
FIG. 1 illustrates a construction of a conventional parallel Metal-Insulator-Metal (MIM) capacitor 100 whose first and second MIM capacitors 110 and 120 are connected in parallel.
As shown in FIG. 1, the conventional parallel MIM capacitor 100 has a simple construction but, because of a low capacitance density, has a drawback that when it is used in a circuit requiring high capacitance, the whole circuit increases in volume.
As a solution to such a problem, there is provided a series Metal-Oxide Semiconductor (MOS) capacitor.
FIG. 2 illustrates a construction of a conventional series Metal-Oxide-Semiconductor (MOS) capacitor 200 whose first and second MOS capacitors 210 and 220 are connected in series. An equivalent resistor (R) of more than 500 kΩ is interposed between the first and second MOS capacitors 210 and 220. The equivalent resistor (R) serves to operate the first or second MOS capacitors 210 and 220 in a strong inversion region. However, even in this construction, there occurs a drawback that a volume is not effectively reduced because of the equivalent resistor (R).